This invention relates generally to video surveillance systems and, more particularly, to assembling and disassembling camera pan, tilt, and zoom assemblies.
At least some known video surveillance systems include one or more video cameras mounted in a housing along with a pan, tilt, and zoom (PTZ) assembly. The PTZ permits controlling a movement of the camera to align a viewing area of the camera with an object of interest or location of interest. The zoom portion of the mechanism may be used to adjust a field of view of the camera. The housing protects the camera from the environment in the location where the camera and PTZ assembly are mounted.
During initial installation and periodically thereafter, the camera and/or PTZ assembly may need to be removed from it's mounted location. For example, over time, the camera and/or PTZ assembly may require maintenance to restore a damaged or worn camera or PTZ assembly to an operable condition. When installing, repairing, or replacing a PTZ assembly a maintenance person is frequently required to use two hands to unlatch the mechanism that supports the PTZ assembly and remove it from its housing. At least some known PTZ assemblies are positioned in an elevated location, therefore using two hands to remove the PTZ assembly creates a safety hazard. In addition, when installing, repairing, or replacing a PTZ assembly a maintenance person is frequently required to push and/or pull with a great amount of force to install or remove the PTZ assembly from its housing. Such actions can cause a safety hazard by unbalancing a person high in the air on a ladder or lifting mechanism. Requiring the use of a man-lift or other lifting mechanism, so that two hands may be used also increases the cost of removing and installing the camera and PTZ assembly.
At least some known PTZ assemblies are compact in size such that various hazards can arise from placing a hand into these mechanisms, for example, to loosen fasteners, catches, and/or latches, or during insertion and removal of the PTZ assembly. A part of the PTZ assembly falling from the elevated mounting position can create a safety hazard as well. A PTZ assembly falling from an elevated position could cause death or serious bodily injury such that positive control and installation of the PTZ assembly is required. At least some known PTZ attachment mechanisms create a “false positive” indication of attachment, such that the user believes the mechanism is securely attached in place when it is not.
A previous attempt to address the afore mentioned problems included a radial handle located inside the PTZ assembly housing. When pulled, the handle would engage symmetrical pawls on leaf springs releasing the PTZ mechanism. However, an uneven distribution of downward forces, sometimes caused binding between the engaged components and inserting a hand into the housing created a safety hazard for the user and limited the compactness of the design. A second attempt to address the problems described above included a toothed bracket that was constrained to linear motion tangent to a shroud of the PTZ assembly. The shroud was also toothed, and when engaged, the teeth would align and the bracket could be moved. The bracket included a wedge design that would move over a stubby nose spring plunger, creating the upward force necessary to hold the PTZ assembly in place. However, the linear motion of the bracket causes binding because the motion of the shroud was radial and the latching of the PTZ assembly is not positive such that the user is required to apply a force to engage the latch.